Push start

Source: Wikipedia, the free encyclopedia.
The Honker II, a midget racing car, getting a push start at the 144th Wagga Wagga Show.
A group of people attempting to push start a motorcycle.

Push starting, also known as bump starting, roll starting, clutch starting, popping the clutch or crash starting, is a method of starting a

automobile self starter, kick start, jump start etc.) are unavailable.[2]

The most common way to push start a vehicle is to put the manual transmission in second gear, switching the ignition to on/run, depressing the clutch, and pushing the vehicle until it is at a speed of 5 to 10 mph (8 to 16 km/h) or more, then quickly engaging the clutch to make the engine rotate and start while keeping the gas pedal partially depressed, then quickly disengaging the clutch so it does not stall.

Types

Push starting is most successful when the automobile is using a

battery providing some electricity since fuel injection
systems must have power to operate.

Automatic or manual gearbox

A vehicle equipped with an automatic transmission (including semi-automatic (clutchless manual) transmissions) is difficult to push start since selection of transmission gears is possible only when the internals of such a gearbox are rotating. However, automatics with both front and rear hydraulic pumps can be push-started with no problems. The last American automobile with this type of transmission was the 1969 Chevrolet Corvair with a Powerglide automatic. While push-start can cause more damage to a hydrolocked engine, the starter motor is limited.[3]

Petrol or diesel engines

A diesel engine uses heat and high compression (

glowplugs
to preheat the cylinder(s). If a battery is completely discharged then it may not provide the necessary power to heat the glowplugs, making the push starting of a diesel vehicle with a depleted battery almost impossible.

Fuel delivery systems

Fuel injection is most common for modern gasoline and diesel engines.

automobile self starter
then it may also not be possible to activate the injectors. The most common method to start such a vehicle engine is to jump start it.

A

fuel pump
is used for fuel injection. It can be mechanically driven or electrically driven. If electrical then the same problem may arise which the battery cannot turn the pump because it is heavily discharged. A carburetor only needs suction from the internal combustion engine to work best when push starting. Once the engine is running, a fuel pump (mechanical or electrical) will continue to supply fuel to the carburetor.

Carburetor engines may damage the catalytic converter by fuel when cranked longer without igniting fuel or electrical controlling the carburetor.

Ignition systems

A modern gasoline engine contains an electronic ignition system which precisely times the electrical pulse to the spark plug. The advantage of such a device is that it can deliver a full power electrical pulse to the spark plugs even when the alternator is turning very slowly (as in push starting a motor). The outdated method of a mechanically timed ignition system is that it cannot deliver a full electrical pulse at very low engine revolutions per minute (RPM). This may affect the ease of push starting an engine to life.

History

In the early 20th century, many motorcycles could only be push started; the 1908 Scott was distinguished by introducing a kick starter feature.[4] Excelsior Motor Company's Welbike, intended to be carried by paratroopers in World War II, was designed to be started only by push starting.[4]

References

  1. ^ "Driving Tips - Workshops". Archived from the original on 2007-11-04. Retrieved 2007-10-02. Driving Tips - Workshops
  2. ^ Whitehead, Louis. "Dealing with a Dead Car Battery". AskMen.com. Retrieved May 12, 2020.
  3. ISBN 9781284109955
    .
  4. ^
    ISBN 0-8018-8530-2
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